WO1991017707A1 - Expiratory flow measuring device - Google Patents
Expiratory flow measuring device Download PDFInfo
- Publication number
- WO1991017707A1 WO1991017707A1 PCT/GB1991/000793 GB9100793W WO9117707A1 WO 1991017707 A1 WO1991017707 A1 WO 1991017707A1 GB 9100793 W GB9100793 W GB 9100793W WO 9117707 A1 WO9117707 A1 WO 9117707A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- vane
- pointer
- rest position
- baffle
- airflow
- Prior art date
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/08—Detecting, measuring or recording devices for evaluating the respiratory organs
- A61B5/087—Measuring breath flow
- A61B5/09—Measuring breath flow using an element rotated by the flow
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/08—Detecting, measuring or recording devices for evaluating the respiratory organs
- A61B5/087—Measuring breath flow
- A61B5/0871—Peak expiratory flowmeters
Definitions
- This invention relates to an expiratory flow measuring device. More particularly, it relates to a device for measuring the maximum flow rate of a single forced expiration.
- the present invention may broadly be said to consist in an expiratory flow measuring device for measuring the maximum flow rate of a single forced expiration
- an expiratory flow measuring device for measuring the maximum flow rate of a single forced expiration
- an elongated hollow body having an inlet end and an outlet end; a shaft mounted within the body between the inlet and outlet ends thereof; a vane mounted to said shaft and rotatable within said body away from a defined rest position, said vane being shaped such that airflow through the body from the inlet end past the vane causes the vane to be rotatably displaced from said rest position; and indicator means co-operable with the vane to indicate the extent of maximum displacement of the vane from the rest position.
- the body of the device is substantially tubular.
- the shaft is mounted substantially parallel to the longitudinal axis of the body with said vane being rotatable thereabout.
- the plane of rotation of the vane about the shaft is therefore at substantially 90° to both the longitudinal axis of the body and the direction of airflow through the body.
- the device include a baffle positioned within the body intermediate the inlet end of the body and the vane, which baffle is provided to direct the airflow into a generally annular volume within the body.
- the device can also conveniently include biasing means to urge the vane towards its rest position.
- the device includes a mouthpiece engageable with the inlet end of the body and through which air expired by a patient can pass into the body.
- Figure 1 is a side elevational view partly in section of a preferred form of the device
- Figure 2 is an elevational view of the device of Figure 1 from the outlet end
- Figure 3 is a detail of various components of the device of Figure 1.
- the present invention relates to a device for reliably and accurately measuring the peak expiratory flow rate of a patient with asthma in order to provide the patient with an objective assessment of airway obstruction.
- This assessment particularly during an asthma attack, allows the patient to monitor the severity of the attack and to determine the appropriate action to be taken.
- This action may involve the self-application of a pre-deter ined dosage of asthma medication or, in the case of a severe attack, the seeking of urgent medical assistance.
- the first component of the device is an elongated hollow body. As shown in Figures 1 and 2 of the accompanying drawings it is preferred that this body 10 be substantially tubular. However, other appropriate shapes for the body are in no way intended to be excluded.
- Body 10 has an inlet end 12 and an outlet end 14. Between inlet end 12 and outlet end 14 there is provided a shaft 16 which is preferably disposed substantially parallel to the longitudinal axis of body 10.
- a vane 18 is carried by shaft 16 and is rotatable within the body. As shown in Figure 3, this rotatability is achieved through the mounting of vane 18 to hub 20 which is itself rotatable about shaft 16. Conveniently, retarding friction when hub 20 and in turn vane 18 are rotating about shaft 16 is minimised by the provision of bearings 22 and 24.
- Vane 18 is shaped such that airflow through body 10 from inlet end 12 causes, vane 18 to be rotatably displaced from a defined rest position. Conveniently, this is achieved by orienting the plane of vane 18 at about 45° to the longitudinal axis of body 10.
- the rest position of the vane can be defined by any suitable means.
- the rest position of the vane is defined by a stop 26.
- the device of the invention further includes indicator means to indicate the extent of the displacement of the vane from its rest position.
- the indicator means is co-operable with the vane of the device to indicate the peak angular displacement of the vane.
- the indicator means comprises a radial pointer 28 which is again carried by shaft 16 and which is associated with a circumferential scale 30 provided on the internal surface of tubular body 10. Scale 30 is appropriately graduated to indicate the extent of airway restriction for the patient using the device.
- the indicator means be resettable to a zero position which corresponds to the rest position of vane 18.
- the indicator means further includes manual reset means in the form of a knob 32. Details of the construction of the indicator means are shown in Figure 3. As illustrated, shaft 16 is provided at one end with knob 32 and associated retaining ring 34 which are both fixed to the shaft. A pointer-bearing ring 36 carrying pointer 28 and a friction ring 38 are also provided which turn freely on the shaft 16.
- knob 32 there is a bore 40 which houses a cylindrical pressure spring 42 which presses lightly against friction ring 38. The extent of movement of spring 42 is limited by the retaining ring 34 attached to shaft 16.
- Radial pointer 28 and vane 18 are made co-operable through the engagement of the pointer and the trailing edge of the vane. In this way, rotation of vane 18 from its rest position causes pointer 28 to be similarly rotated from its zero position to a position on circumferential scale 30. As shown, this engagement between vane 18 and pointer 28 is preferably achieved by provision of a tab 44 on the trailing edge of the vane. This is of course not critical as vane 18 could directly engage pointer 28 or alternatively tab 44 could be provided on the pointer itself.
- the device further includes a baffle.
- the baffle is positioned within the body between the inlet end and the vane and is shaped to direct airflow into a generally annular volume within the body. Directing the airflow in this way increases the efficiency of operation and accuracy of the device.
- baffle 46 is preferably of a general conical shape to reduce turbulence with the apex of the cone towards the inlet end 12 of the body 10.
- baffle 46 is mounted within the body 10 by three pegs 48 which are equidistantly spaced around the inner diameter of body 10 and which are of dimensions so as to not substantially disrupt the airflow through the body.
- baffle 46 provides the mounting for shaft 16. Details of this mounting are shown in Figure 3.
- baffle 46 be shaped such that as vane 18 turns, progressively less area of the vane is exposed to the airflow. This is conveniently achieved by providing baffle 46 with its basal section describing a spiral plane as shown in Figure
- biasing means are provided to urge the vane towards its rest position at stop 26.
- the biasing means is conveniently a hair spring 56 although this is not critical.
- the spring is conveniently located within an appropriate recess 58 provided in the base of baffle 46 with the ends of the spring being attached to hub 20 and baffle 46 respectively.
- the point of maximum possible angular displacement from the rest position is preferably also defined.
- this is achieved through the provision of a stop
- baffle 46 which is co-operable with the trailing edge of vane
- the device of the invention includes a mouthpiece through which a patient can blow.
- This mouthpiece is preferably releasably engageable with the inlet end 12 of the body 10 of the device for reasons of hygiene.
- the mouthpiece 60 is a substantially tubular hollow body of a similar albeit slightly reduced diameter compared to that of body 10, the external surface of mouthpiece 60 being slidably engageable with the internal surface of body 10.
- mouthpiece 60 which engages body 10 is provided with flow directing means in the form of annular deflector
- This deflector is included to centrally direct the airflow onto baffle 46.
- the location of the deflector 62 with respect to the baffle 46 may be adjusted in order to cover different ranges of airflow according, for example, to the needs of a particular user group.
- the patient can then obtain an objective assessment of the extent of his or her airway obstruction from a comparison of the position of pointer 28 with graduated scale 30.
- the variability of this device was compared with a Wright Peak Flow Meter.
- the device was connected in series with the Wright Peak Flow Meter so that the maximum flow rate during forced expiration was simultaneously measured on both instruments.
- One investigator undertook 133 consecutive expiratory manoeuvres with different degrees of effort to achieve a range of values recorded on the Wright Peak Flow Meter from 75 to 655 litres per minute.
- a comparison of paired values obtained with the new device and the Wright Peak Flow Meter was undertaken and demonstrated a correlation coefficient (r) of 0.99.
- a peak expiratory flow measuring device which will quickly and accurately provide a patient with an objective assessment of the obstruction of his or her airway. This is particularly useful during an asthma attack as it will enable the patient to assess the severity of the attack and to take the necessary steps depending on the assessment obtained. This will be an invaluable aid to the patient in self-monitoring his or her condition.
- the device of the invention is particularly accurate and sensitive over a range of expiratory flow rates due to the provision and shape of the baffle.
- the sensitivity of the device is greatest at low flow rates due to the exposure of almost the entire area of the vane to the airflow whereas at greater flow rates a progressively decreasing area of the vane is exposed. In this way a wide range of airflows can be measured without losing the desirably sensitive measurement of low airflows.
- the device of the invention also has the most important advantage of being able to function effectively when made of a comparable size to a conventional inhaler. This small size of the device makes it truly portable in the sense of being able to be carried in a pocket or purse of a patient. This portability will enable the patient to carry the device without the inconvenience associated with other larger and heavier devices which will mean that the present device is much more likely to be at hand whenever and wherever the patient suffers an asthma attack. This continual availability of the device is essential to any self-management programme the patient may follow.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Biomedical Technology (AREA)
- Molecular Biology (AREA)
- Pulmonology (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- Engineering & Computer Science (AREA)
- Physiology (AREA)
- Heart & Thoracic Surgery (AREA)
- Medical Informatics (AREA)
- Physics & Mathematics (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
- Investigating Or Analysing Biological Materials (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/952,864 US5413112A (en) | 1990-05-21 | 1991-05-21 | Expiratory flow measuring device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NZ233745A NZ233745A (en) | 1990-05-21 | 1990-05-21 | Single forced expiration airflow meter with rotating vane: maximum airflow indication retained until meter reset |
NZ233745 | 1990-05-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1991017707A1 true WO1991017707A1 (en) | 1991-11-28 |
Family
ID=19923250
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB1991/000793 WO1991017707A1 (en) | 1990-05-21 | 1991-05-21 | Expiratory flow measuring device |
Country Status (6)
Country | Link |
---|---|
US (1) | US5413112A (en) |
EP (1) | EP0530239A1 (en) |
AU (1) | AU7868191A (en) |
CA (1) | CA2083510A1 (en) |
NZ (1) | NZ233745A (en) |
WO (1) | WO1991017707A1 (en) |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5816246A (en) * | 1994-09-15 | 1998-10-06 | Mirza; M. Zubair | Electronic pocket spirometer |
US5581041A (en) * | 1995-04-18 | 1996-12-03 | Bouchillon; Jerry L. | Apparatus for measuring flow of granular particles in conduit |
US6126613A (en) * | 1999-02-08 | 2000-10-03 | Edwards; Raymond A. | Device and method to measure inhalation and exhalation air flows |
US6447459B1 (en) | 2000-04-07 | 2002-09-10 | Pds Healthcare Products, Inc. | Device and method for measuring lung performance |
US6942625B1 (en) | 2002-05-11 | 2005-09-13 | Terry Keith Bryant | Incentive spirometry devices by the employment of verbal simulated humanlike voices |
US8251876B2 (en) | 2008-04-22 | 2012-08-28 | Hill-Rom Services, Inc. | Breathing exercise apparatus |
US8539951B1 (en) | 2008-05-27 | 2013-09-24 | Trudell Medical International | Oscillating positive respiratory pressure device |
CA2837057C (en) | 2011-06-06 | 2018-08-28 | Trudell Medical International | Oscillating positive expiratory pressure device |
US9180271B2 (en) | 2012-03-05 | 2015-11-10 | Hill-Rom Services Pte. Ltd. | Respiratory therapy device having standard and oscillatory PEP with nebulizer |
US9517315B2 (en) | 2012-11-30 | 2016-12-13 | Trudell Medical International | Oscillating positive expiratory pressure device |
US9849257B2 (en) | 2013-08-22 | 2017-12-26 | Trudell Medical International | Oscillating positive respiratory pressure device |
US10953278B2 (en) | 2018-02-02 | 2021-03-23 | Trudell Medical International | Oscillating positive expiratory pressure device |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1344836A (en) * | 1971-04-19 | 1974-01-23 | Ferraris Dev Eng Co Ltd | Peak flow meters |
GB1351112A (en) * | 1970-05-29 | 1974-04-24 | Ferraris Dev Eng Co Ltd | Apparatus for indicating the rate of fluid flow |
GB2024628A (en) * | 1978-07-03 | 1980-01-16 | Scitec Corp Pty | Spirometer and turbine transducer therefor |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2296973A (en) * | 1941-01-13 | 1942-09-29 | Eugene M Ardelt | Anemometer |
FR1096098A (en) * | 1954-03-19 | 1955-06-08 | Symmetrical inspiro-expiro-meter device | |
US2889707A (en) * | 1955-10-28 | 1959-06-09 | Walter J Snider | Anemometer |
DE2614752C2 (en) * | 1976-04-06 | 1983-11-17 | Eugen 7821 Eisenbach Grieshaber | Spirometer |
US4679566A (en) * | 1985-02-08 | 1987-07-14 | Tamm Ulf S | Apparatus for measuring pulse rate, vital capacity and pulmonary peak flow |
WO1989012423A1 (en) * | 1988-06-17 | 1989-12-28 | Adx Systems Pty Limited | Monitoring system |
-
1990
- 1990-05-21 NZ NZ233745A patent/NZ233745A/en unknown
-
1991
- 1991-05-21 EP EP91909401A patent/EP0530239A1/en not_active Withdrawn
- 1991-05-21 WO PCT/GB1991/000793 patent/WO1991017707A1/en not_active Application Discontinuation
- 1991-05-21 CA CA002083510A patent/CA2083510A1/en not_active Abandoned
- 1991-05-21 US US07/952,864 patent/US5413112A/en not_active Expired - Fee Related
- 1991-05-21 AU AU78681/91A patent/AU7868191A/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1351112A (en) * | 1970-05-29 | 1974-04-24 | Ferraris Dev Eng Co Ltd | Apparatus for indicating the rate of fluid flow |
GB1344836A (en) * | 1971-04-19 | 1974-01-23 | Ferraris Dev Eng Co Ltd | Peak flow meters |
GB2024628A (en) * | 1978-07-03 | 1980-01-16 | Scitec Corp Pty | Spirometer and turbine transducer therefor |
Also Published As
Publication number | Publication date |
---|---|
AU7868191A (en) | 1991-12-10 |
EP0530239A1 (en) | 1993-03-10 |
US5413112A (en) | 1995-05-09 |
NZ233745A (en) | 1993-02-25 |
CA2083510A1 (en) | 1991-11-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5413112A (en) | Expiratory flow measuring device | |
Clark | The use of laser diffraction for the evaluation of the aerosol clouds generated by medical nebulizers | |
US5357975A (en) | Device for measuring the flow-volume of pulmonary air | |
WO2016152847A1 (en) | Urine flow meter | |
US9763626B2 (en) | Acoustic spirometer system | |
US3949737A (en) | Spirometer | |
Corcoran et al. | Optical measurement of nebulizer sprays: a quantitative comparison of diffraction, phase Doppler interferometry, and time of flight techniques | |
Broeders et al. | In check dial: accuracy for Diskus and Turbuhaler | |
CN201564480U (en) | Lumbar mobility survey meter | |
US5320107A (en) | Spirometer with zone graph | |
US6889564B1 (en) | Peak flow meter | |
WO1996020642A1 (en) | Miniature peak flow meter | |
AU2015305032B2 (en) | Spirometer | |
JPH10509891A (en) | Peak flow meter | |
EP0769303A2 (en) | Combined inhaler und peak flow meter | |
US4144883A (en) | Spirometer | |
Shephard | Pneumotachographic measurement of breathing capacity | |
CN212438610U (en) | Inhalation peak flow meter for simulating inhaler resistance | |
JP7260865B2 (en) | Composite urometer | |
Olson et al. | Development and calibration of a low-flow version of the Marple-Miller impactor (MMI™) | |
KR100682026B1 (en) | down-sized single directional respiratory air flow measuring tube | |
EP2081491A1 (en) | Down-sized single directional respiratory air flow measuring tube | |
Wang et al. | Simple instrument for evaluating pulmonary ventilatory function | |
JP3594722B2 (en) | Ventilation meter | |
Depledge | Peak inspiratory flow: measurement using a modified mini Wright peak flow meter. |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AU BB BG BR CA FI HU JP KP KR LK MC MG MW NO PL RO SD SU US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE BF BJ CF CG CH CI CM DE DK ES FR GA GB GR IT LU ML MR NL SE SN TD TG |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2083510 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1991909401 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1991909401 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1991909401 Country of ref document: EP |